Dr. Klaus Heinz of HEDD Audio (ex ADAM Audio) - measuring speakers, in particular speaker dynamics

[andreasmaaan]

I agree, 3-way floorstander is not really big, I consider it "medium". But I don't really agree with the 120dB+ criteteria as we are speaking about speakers to be used in homes (or we are not?). In that terms I would suggest that maybe a lowest frequency that a speaker can play with -3dB or -6dB is used as a criteria to characterise it's "size". In that case the division could look something like this:

>50Hz - small speakers
>40Hz - smaller medium speakers
>30Hz - large medium speakers
>20Hz - large speakers

By that criteria LS50 with a decent subwoofers (preferrably at least one for each speaker) would become a large speaker.

That would make the Devlialet Phantom a "big" speaker though

Seriously though, the 120dB+ wasn't really supposed to be a criterion, but more a practical result that follows from using drivers that large. It's the size of the box and drivers that I intended to put forward as criteria.

 

[Krunok]

Seriously though, the 120dB+ wasn't really supposed to be a criterion, but more a practical result that follows from using drivers that large. It's the size of the box and drivers that I intended to put forward as criteria.

I understand your argument, but here is what I meant: for example, pair of LS50 + pair of Rythmik Audio subs can easilly reach 20Hz-20khz linearity at 95dB but I am not sure if that combo can produce 120dB. On the other hand some large speakers for outdoor use can easilly reach 120+dB but cannot reach 20Hz. In that context i proposed low frequency as a criteria for "big" home speaker and not max SPL.

That would make the Devlialet Phantom a "big" speaker though

I would very much like to hear impressions from a user who owns a pair of them if they produce "big" sound.

I think that fellow who used to work with F1 racing cars has a pair of them but I can't remember his name this moment.

 

[andreasmaaan]

I understand your argument, but here is what I meant: for example, pair of LS50 + pair of Rythmik Audio subs can easilly reach 20Hz-20khz linearity at 95dB but I am not sure if that combo can produce 120dB. On the other hand some large speakers for outdoor use can easilly reach 120+dB but cannot reach 20Hz. In that context i proposed low frequency as a criteria for "big" home speaker and not max SPL.

Lots of ways to cut the cake I suppose. The thing is, my personal opinion is that high max. SPL, low distortion and good linearity at high SPLs is much more important than extension below 30Hz.

I would say that though, given my own system which has high max. SPL but only moderate bass extension. I don't listen to much organ music, however.

But anyway, I agree with you that max. SPL is not the correct criterion - which is why I proposed literal size as the defining thing and mentioned max. SPL only as a byproduct.

 

[Krunok]

Lots of ways to cut the cake I suppose. The thing is, my personal opinion is that high max. SPL, low distortion and good linearity at high SPLs is much more important than extension below 30Hz.

I would say that though, given my own system which has high max. SPL but only moderate bass extension. I don't listen to much organ music, however.

But anyway, I agree with you that max. SPL is not the correct criterion - which is why I proposed literal size as the defining thing and mentioned max. SPL only as a byproduct.

Let's try to discuss this from another angle. Pls take a moment to look at the Kef Reference series web page, at models Reference 5 (big speaker, even by size), Reference 1 (small speaker) and Reference 8B. The question here is how would pair of Reference 5 compare against pair of Reference 1 + pair of Reference 8B subs. The later combo wouldn't still match size of Reference 5 but it would most probably match everything else (LF extension, linearity, max SPL, distortion). They would probably have similar Spinorama graphs too. So, does adding a 8B sub to Reference 1 small speaker make it big?

 

[Soniclife]

That would make the Devlialet Phantom a "big" speaker though

They used to list more useful extension specifications on the website, at different output levels, they don't anymore, but that extension was not maintained at decent levels, as you would expect. They still produce a staggering amount of bass for the overall size, probably more than most floorstanders can manage.

 

[svart-hvitt]

Lots of ways to cut the cake I suppose. The thing is, my personal opinion is that high max. SPL, low distortion and good linearity at high SPLs is much more important than extension below 30Hz.

I would say that though, given my own system which has high max. SPL but only moderate bass extension. I don't listen to much organ music, however.

But anyway, I agree with you that max. SPL is not the correct criterion - which is why I proposed literal size as the defining thing and mentioned max. SPL only as a byproduct.

I saw what you wrote about your preferences. So I wondered, is this a «big» speaker in your estimation?

https://www.genelec.com/sites/default/files/media/s360_operating_manual.pdf

Long term SPL @ 112 dB, peaks at 128 dB (!!!), but rolls off fast @ ca. 35 Hz.

 

[Krunok]

They still produce a staggering amount of bass for the overall size, probably more than most floorstanders can manage.

Yes, I believe they do. But I don't think they can match a sub like Reference 8B.

 

[svart-hvitt]

They used to list more useful extension specifications on the website, at different output levels, they don't anymore, but that extension was not maintained at decent levels, as you would expect. They still produce a staggering amount of bass for the overall size, probably more than most floorstanders can manage.

I wondered, how would the Phantoms fare with a couple of big subs and DSP...

Probably pretty high distortion still above ca. 100 Hz?

 

[andreasmaaan]

Let's try to discuss this from another angle. Pls take a moment to look at the Kef Reference series web page, at models Reference 5 (big speaker, even by size), Reference 1 (small speaker) and Reference 8B. The question here is how would pair of Reference 5 compare against pair of Reference 1 + pair of Reference 8B subs. The later combo wouldn't still match size of Reference 5 but it would most probably match everything else (LF extension, linearity, max SPL, distortion). They would probably have similar Spinorama graphs too. So, does adding a 8B sub to Reference 1 small speaker make it big?

I don't think so actually. The spec sheet states that the Reference 1's max SPL is 111dB, while the 8B's max SPL is 110dB and it's -3dB point is 24Hz. The Reference 5's max SPL is 116dB, while it's -6dB point is 35Hz (so presumably a -3dB point of around 40Hz).

More importantly, the woofer-mid crossover frequency for both the Reference 1 and the Reference 5 is 350Hz. This means that, even with a subwoofer added, the reference 5 has 4x the driver surface area between the sub crossover frequency and 350Hz.

In other words, even if you add a sub to the Reference 1, its output will still be limited in the upper-bass/lower-mirange compared to a Reference 5.

 

[Krunok]

I don't think so actually. The spec sheet states that the Reference 1's max SPL is 111dB, while the 8B's max SPL is 110dB and it's -3dB point is 24Hz. The Reference 5's max SPL is 116dB, while it's -6dB point is 35Hz (so presumably a -3dB point of around 40Hz).

More importantly, the woofer-mid crossover frequency for both the Reference 1 and the Reference 5 is 350Hz. This means that, even with a subwoofer added, the reference 5 has 4x the driver surface area between the sub crossover frequency and 350Hz.

In other words, even if you add a sub to the Reference 1, its output will still be limited in the upper-bass/lower-mirange compared to a Reference 5.

You are correct, but as I said, with home use I don't really think SPL above 110dB matters as most folks would never use it - I know I haven't.
Maybe it is your DJ work in the clubs that makes you focused on SPLs above 110dB?

So, if we accept 110dB as max reasonable home SPL I think we can agree that from your analysis it also turns out that Reference 1 + 8B would go noticeably deeper than Reference 5 - and that might matter to most home users.

 

[andreasmaaan]

I saw what you wrote about your preferences. So I wondered, is this a «big» speaker in your estimation?

https://www.genelec.com/sites/default/files/media/s360_operating_manual.pdf

Long term SPL @ 112 dB, peaks at 128 dB (!!!), but rolls off fast @ ca. 35 Hz.

I'd call it "medium", and I'd suggest the specs are misleading

The 128dB peak figure is stated as "Maximum peak acoustic output per pair in a listening room with music material at 1m".

So a rather nebulous figure, IMHO.

This graph, elsewhere in the document, is more to the point. It suggests that the speaker can hit 117-118dB at 1m anechoically.

 

[Krunok]

I'd call it "medium", and I'd suggest the specs are misleading

The 128dB peak figure is stated as "Maximum peak acoustic output per pair in a listening room with music material at 1m".

So a rather nebulous figure, IMHO.

This graph, elsewhere in the document, is more to the point. It suggests that the speaker can hit 117-118dB at 1m anechoically.

View attachment 27410

But Andreas, I really think nobody needs more SPL than 110dB at home. But reference 1 + 8B combo would provide noticeably lower bass extension which some users would appreciate and which may sound "bigger" than Reference 5.

 

[Soniclife]

In other words, even if you add a sub to the Reference 1, its output will still be limited in the upper-bass/lower-mirange compared to a Reference 5.

I've wondered if this is the frequency range that might be most of interest to this discussion. Adding massive amounts of bass with subs can get you any headroom you want lower down, but would take stereo subs and careful integration to support this range, that 3 way speakers with a largish bass driver are good at, even if their ultimate extension cannot match a sub.

 

[svart-hvitt]

I'd call it "medium", and I'd suggest the specs are misleading

The 128dB peak figure is stated as "Maximum peak acoustic output per pair in a listening room with music material at 1m".

So a rather nebulous figure, IMHO.

This graph, elsewhere in the document, is more to the point. It suggests that the speaker can hit 117-118dB at 1m anechoically.

View attachment 27410

For certain effects, say in films, peaks can be of very short duration. Certain transients, particularly higher frequencies, can also be present in music material. So I think 128 dB short term is of interest to anyone discussing dynamics (which was the theme of this thread at the outset).

Being able to pump out sound at high SPLs over time is another business altogether, and that’s where 112 dB max is of relevance. But that has little to do with dynamics.

 

[Krunok]

.. but would take stereo subs and careful integration to support this range.

The assumption is it is done exactly that way, as @mitchco demonstrated with 2 subs and integration made with Audiolense.

 

[Soniclife]

I wondered, how would the Phantoms fare with a couple of big subs and DSP...

Probably pretty high distortion still above ca. 100 Hz?

I've not seen distortion measurements of them, I'm not sure what to expect.
I have heard them properly, they are good speakers, the software seems to be very flaky though.

 

[andreasmaaan]

You are correct, but as I said, with home use I don't really think SPL above 110dB matters as most folks would never use it - I know I haven't.
Maybe it is your DJ work in the clubs that makes you focused on SPLs above 110dB?

So, if we accept 110dB as max reasonable home SPL I think we can agree that from your analysis it also turns out that Reference 1 + 8B would go noticeably deeper than Reference 5 - and that might matter to most home users.

Haha, I agree, and in my living room where I don't listen at realistic levels I would prefer the bass extension and placement flexibility of the Reference 1 + subs.

But regarding that 110dB peak SPL figure, I want to make two points anyway.

Firstly, even if you "only" want to hit 110dB peaks (which is loud, but not crazy loud for dynamic classical music at realistic SPLs), your Reference 1 woofer is going to be stressed in the band between 80 and 350Hz compared to the 4 woofers in the Reference 5. So distortion and non-linearity may become factors well before the speaker reaches its maximum SPL.

Secondly, looking at this another way, the 8B houses 2 x 9" woofers compared to the 4 x 6.5" woofers in the Reference 5. That's probably about the same total surface area per side. This suggests that the two setups are in some ways equivalent in terms of size, with the 8B trading max SPL for bass extension and vice-versa.

But Andreas, I really think nobody needs more SPL than 110dB at home. But reference 1 + 8B combo would provide noticeably lower bass extension which some users would appreciate and which may sound "bigger" than Reference 5.

I'm not suggesting though that you would want to play louder than this at home, just that if you do have peaks this loud (which you would if you listen orchestral music at realistic levels), you might not want the woofers in your mains to be on the verge of meltdown.

But yeh, I would agree with you in the case of my living room at least, where we don't listen at realistic levels, and especially given the placement flexibility you get with subs.

 

[Soniclife]

The assumption is it is done exactly that way, as @mitchco demonstrated with 2 subs and integration made with Audiolense.

Did he say what crossover frequency was used? I'm thinking to make it work amazingly maybe 200 or higher might be required.

 

[andreasmaaan]

For certain effects, say in films, peaks can be of very short duration. Certain transients, particularly higher frequencies, can also be present in music material. So I think 128 dB short term is of interest to anyone discussing dynamics (which was the theme of this thread at the outset).

Being able to pump out sound at high SPLs over time is another business altogether, and that’s where 112 dB max is of relevance. But that has little to do with dynamics.

But again, the spec sheet places piles of caveats on that 112dB figure: "Maximum long term RMS acoustic output... in half space, averaged from 100 Hz to 3 kHz...with IEC weighted noise (limited by driver protection circuit) at 1m"

In other words, this speaker is not "large" by any measure, and will need a sub to play low and loud.

 

[Krunok]

Firstly, even if you "only" want to hit 110dB peaks (which is loud, but not crazy loud for dynamic classical music at realistic SPLs), your Reference 1 woofer is going to be stressed in the band between 80 and 350Hz compared to the 4 woofers in the Reference 5. So distortion and non-linearity may become factors well before the speaker reaches its maximum SPL.

I don't think that would be the case. I would expect reference 1 speakers to handle 110 peaks with comfortable ease in the 80-350Hz. Besides, accoring to specs 8B can be set to handle frequencies up to 160Hz so Reference 1 would be left to handle from 160Hz upwards and that certainly shouldn't be a problem for SPL up to 110dB.